WO2005022729A1

WO2005022729A1 - Electromagnetic actuator

Info

Publication number: WO2005022729A1
Application number: PCT/JP2004/012295
Authority: WO
Inventors: Hisashi Kawamoto; Satoru Tada; Takashi Nakano
Original assignee: Seiko Precision Inc.
Priority date: 2003-08-29
Filing date: 2004-08-26
Publication date: 2005-03-10
Also published as: KR20060032218A; US7511391B2; KR100695256B1; CN100495873C; US20060145798A1; CN1839531A; JP4620590B2; JPWO2005022729A1

Abstract

An electromagnetic actuator (1) including a rotor (2) and a stator (3) on which coils (4, 5) are wound, the coils being arranged so as to face portions of the outer periphery of the rotor (2). The stator is substantially letter C-shaped, and the rotor (3) is placed such that a rotating shaft (21) of the rotor (2) is present in a space surrounded by the stator (3). When an imaginary standard line (BL) passing through the position of the rotating shaft (21) and separating the stator (3) to the left and the right is set, each of both end portions (11, 12) of the stator is formed within a predetermined angular range on both sides of the standard line (BL) with the position of the rotating shaft as the center (CT). In the electromagnetic actuator (1), since the end portions (11, 12) are arranged within the predetermined range, the coils can be efficiently wound on the stator without obstacle.

Description

Specification

Ta

Technical field

The present invention relates to a small electromagnetic actuator used in an optical device such as a camera. More specifically, the present invention relates to an electromagnetic actuator provided with a stator having a shape capable of efficiently performing coil winding in a manufacturing process while ensuring the function of the electromagnetic actuator itself.

^ Scenic technology

[0002] For example, a shutter device built in an autofocus camera is driven by an electromagnetic actuator. In recent years, the reduction in size and weight of cameras has been promoted at a remarkable speed, and it is necessary to provide small and highly accurate electromagnetic actuators. Patent Literature 1 discloses an electromagnetic actuator that simultaneously excites two coils provided on a stator to rotate a rotor.

FIG. 4 is a plan view schematically showing an electromagnetic actuator 100 disclosed in Patent Document 1. On the outer periphery of the rotor 101, an equipod trapezoidal stator 103 is arranged. This stator 103 has three magnetic poles 104, 105, and 106. A first coil 108 and a second coil 109 are provided on the left and right, and by controlling the direction of the current supplied to the coils 108 and 109, the direction of the magnetic field is changed to rotate the rotor 101 formed by permanent magnets. Let's do it. The third magnetic pole 106 is adapted to be excited by the left and right coils 108 and 109. In particular, the third magnetic pole 106 has a protruding portion 107 approaching the rotor 101. By providing the protruding portion 107, the N pole (or S pole) of the rotor 101 is positioned at the protruding portion 107 when there is no magnetic field (non-energized).

Patent Document 1: Japanese Patent Publication No. 2-2382

Disclosure of the invention

Problems to be solved by the invention

[0005] In the electromagnetic actuator 100 disclosed in Patent Document 1, almost all of the outer periphery of the rotor 101 is arranged so that the stator 103 surrounds the rotor. Therefore, since the magnetic flux generated from the coils 108 and 109 is transmitted to the rotor 101 without leaking, a strong torque can be obtained. This is an electromagnetic actuator having a preferable structure in that it can be cut.

[0006] However, the electromagnetic actuator 100 has difficulty in manufacturing. As shown in FIG. 4, coils 108 and 109 are arranged on the left and right sides of the stator 103 arranged so as to surround the outer periphery of the rotor 101. In an actual manufacturing process, it is impossible to directly wind a coil around the stator 103 having such a shape. Therefore, when manufacturing the electromagnetic actuator 100, for example, it is necessary to form the stator 103 so as to be separable, prepare the coils 108 and 109 separately, and combine them later. Therefore, in the manufacturing process of the electromagnetic actuator 100, more parts are required than before, and the assembling work is complicated and the number of steps is increased.

[0007] As described above, the electromagnetic actuator 100 is preferable in terms of the function of the electromagnetic actuator. However, in terms of manufacturing, the number of parts increases, and the manufacturing process becomes complicated and increases. There is a serious problem that rises.

[0008] Therefore, an object of the present invention is to provide an electromagnetic actuator having a structure capable of improving efficiency in a manufacturing process while securing the function as an electromagnetic actuator. Means for solving the problem

[0009] The above object is an electromagnetic actuator including a rotor and a stator having a coil wound so as to face a part of the outer periphery of the rotor, wherein the stator has a substantially C-shape. The rotor is arranged such that a rotation axis of the rotor is located in a space surrounded by the stator, and a virtual reference line that passes through the center of the rotation axis and separates the stator left and right is set. In addition, both ends of the stator are formed within a range of 15 degrees or more and 90 degrees or less from both sides of the reference line with respect to the rotation axis.

[0010] According to the present invention, when winding a coil around the stator using the coil winding device in the manufacturing process, the end of the stator, which is an obstacle, is arranged within a range of 15 degrees or more and 90 degrees or less. Thus, the coil can be efficiently wound around the stator without any obstacle. Since the end portion can be set wider in the above angle range, if the end portion is used as a magnetic pole, the original function of the electromagnetic actuator can be sufficiently secured. Therefore, according to the present invention, it is possible to provide an electromagnetic actuator that can be efficiently manufactured while maintaining the original functions of the electromagnetic actuator. [0011] This angle range is set as the maximum range in which the end of the stator does not hinder the winding of the coil wire by the winding device when winding the coil around the stator. Further, it is preferable that the stator has a shape having a shoulder for suppressing the displacement of the coil. With such a stator, the coil can be positioned at a predetermined position when the coil is wound, and the wound coil can be stably held at the predetermined position.

The invention's effect

[0012] As described above, according to the present invention, it is possible to provide an electromagnetic actuator that can maintain the original function of the electromagnetic actuator and can also improve manufacturing efficiency.

Brief Description of Drawings

FIG. 1 is a diagram showing a configuration of a main part of an electromagnetic actuator according to an embodiment.

FIGS. 2 (A) and (B) are diagrams schematically showing a state in which a coil is wound around a stator.

FIG. 3 is a perspective view showing a stator having a preferable shape.

FIG. 4 is a plan view schematically showing a conventional electromagnetic actuator.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a shirt device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a main part of an electromagnetic actuator 1 according to the embodiment.

The electromagnetic actuator 1 includes a rotor 2 disposed in the center and rotatable in both directions, and a stator 3 disposed to face the outside of the rotor 2. The rotor 2 has a circular cross section and a cylindrical shape. The stator 3 is formed integrally with the C-shape in plan view, and substantially corresponds to a reference line BL (this line passes through the center of the rotor 2) as a geometric center line when viewed in plan. It has a symmetrical shape. The rotating shaft 21 of the rotor 2 is arranged in a space surrounded by the C-shaped stator 3, and the rotor 2 is also housed in the internal space.

[0016] Here, the C-shape is a broad concept including a shape in which a part of a closed figure such as a circle, an ellipse, a polygon, or the like, which has a shape approximated by the letter C, is broken. is there. Therefore, in the case of the data 3 shown in FIG. 1, the shape of the data 3 is such that a part of one side of the square is notched. FIG. 1 shows the electromagnetic actuator 1 in a state where the open side of the stator 3, that is, the ends 11 and 12 are arranged on the upper side. [0017] The rotor 2 has a four-pole configuration including two N poles and two S poles. The motor 2 is a permanent magnet magnetized at a position where the same magnetic poles are opposed to each other, and is set so as to be rotatable in both directions around a rotation axis 21. Both end portions 11 and 12 of the stator 3 having the C shape are formed so as to face the peripheral surface of the rotor 2. These ends 11 and 12 become the first magnetic pole 11 and the second magnetic pole 12, respectively. The third magnetic pole 13 is arranged at an intermediate position between the first magnetic pole 11 and the second magnetic pole 12.

[0018] The stator 3 of the electromagnetic actuator 1 is shaped in consideration of manufacturing efficiency. This point will be described. By arranging the first magnetic pole 11 and the second magnetic pole 12 so as to face the outer periphery of the rotor 2 with a larger area, the magnetic flux from the coil can be effectively used as in the conventional electromagnetic actuator shown in FIG. However, if the first magnetic pole 11 and the second magnetic pole 12 are wider than the predetermined width, the coil cannot be wound directly on the stator 3 as described above, and a problem that the production efficiency is significantly reduced occurs. Therefore, in the electromagnetic actuator 1, the shape of the stator 3 is defined in consideration of the production efficiency while securing the functions required of the electromagnetic actuator.

When the electromagnetic actuator 1 is manufactured, coils 4 and 5 are wound on the left and right sides of the drawing of the stator 3. That is, the first coil 4 is wound between the first magnetic pole 11 and the third magnetic pole 13, and the second coil 5 is wound between the second magnetic pole 12 and the third magnetic pole 13. . In this case, the stator 3 of the electromagnetic actuator 1 has the first magnetic pole 11 and the third magnetic pole 13 at the ends thereof identified as obstacles and shapes.

The detailed shape of the stator 3 will be described with reference to FIG. Each of the magnetic poles (both ends) 11 and 12 of the stator 3 is formed so as to be within a predetermined angle range on both sides around the center CT of the rotating shaft 21. Here, the predetermined angle is, for example, 15 degrees or more and 90 degrees or less in both directions from the reference line BL. The shape is specified so that the magnetic poles 11 and 12 exist in the range between them. This angle range is the maximum range in which the coils 4 and 5 can be wound around the stator 3 in the manufacturing process without any obstacles in terms of efficiency and efficiency.

[0021] In the stator 3 shown in Fig. 1, the angle of the side near the reference line BL of the ends 11 and 12 is about 45 degrees from the reference line BL, and the angle j3 of the side far from the reference line BL is about 75 degrees. It is. In the present stator 3, the angle is in the range of 15 to 90 degrees with respect to the reference line BL. This condition is the same for the left and right ends 11,12. Then, since the angle (i3_a) becomes the width of the magnetic pole, the width may be appropriately set according to the magnetic flux to be applied to the rotor 2. Since the predetermined angle range from the reference line BL is quite wide from 15 degrees to 90 degrees, it is possible to sufficiently secure the required magnetic flux.

Here, with reference to FIGS. 2A and 2B, a description will be given of how the coils 4 and 5 are wound around the stator 3 in a manufacturing process. FIGS. 2A and 2B are diagrams schematically showing a state in which a first coil 4 and a second coil 5 are wound around a stator 3. More specifically, FIG. 4 shows how to wind the coil 5 and () shows how to wind the coil 5. In this figure, only a part of the coil winding device is shown. The stator 3 is fixed in a predetermined posture to a fixing jig 51 of the winding device. The coil supply nozzle 52 rotates around the rotation center MC while supplying the copper wire 55 for the coil. By such an operation, the first coil 4 is first wound around the left side of the stator 3 as shown in FIG. Subsequently, the second coil 5 is wound around the right side of the stator 3 as shown in FIG.

As can be understood from this figure, when winding the coil copper wire 55 around the rotor 3, it is necessary to prevent the magnetic poles 11 and 12 of the rotor from interfering with each other. If the width of the magnetic poles 11 and 12 is too large, the coil cannot be wound around the stator 3 using a winding device (not shown). Therefore, in consideration of this point, the electromagnetic actuator 1 specifies the shape of the stator 3 as described above. With the stator 3 included in the electromagnetic actuator 1, the coil can be wound at a high speed using the winding device, and the production can be performed efficiently.

With reference to FIG. 1 again, another configuration of the electromagnetic actuator 1 will be described. The first magnetic pole 11 is excited when the first coil 4 is energized, and the second magnetic pole 12 is excited when the second coil 5 is energized. On the other hand, the third magnetic pole 13 is excited by both the first coil 4 and the second coil 5. Therefore, the excitation state of the third magnetic pole 13 appears as a state in which the state of energization of the first coil 4 and the second coil 5 is combined.

Further, a current control circuit 25 connected to the first coil 4 and the second coil 5 of the electromagnetic actuator 1 is indicated by a dotted line. In the present embodiment, a current for exciting the first coil 4 and the second coil 5 is supplied from the current control circuit 25. Two patterns are set for this current supply. In the first pattern, the current control circuit 25 sends the first A current for exciting both the coil 4 and the second coil 5 is supplied, and the driving state of the rotor 2 is controlled by switching the current supply direction for each coil. In the first pattern, there are a state in which the first magnetic pole 11 and the second magnetic pole 12 are both excited to the same magnetic pole, and a state in which the first magnetic pole 11 and the second magnetic pole 12 are excited to different magnetic poles. At this time, the resulting magnetic field at the third magnetic pole 13 is stronger when both the first magnetic pole 11 and the second magnetic pole 12 are excited to the same magnetic pole. Conversely, when the first magnetic pole 11 and the second magnetic pole 12 are excited to different magnetic poles, the magnetization at the third magnetic pole 13 is canceled out and becomes a non-magnetized state.

In the second pattern, a current for exciting either the first coil 4 or the second coil 5 is supplied from the current control circuit 25, and by switching the current supply direction, the current of the rotor 2 is changed. The driving state is controlled. In the case of the second pattern, only the first magnetic pole 11 side or the second magnetic pole 12 side is excited, and the magnetic pole is switched to the opposite magnetic pole by changing the current supply direction. The third magnetic field 13 in the second pattern is excited by a magnetic pole that is a counter electrode of the excited first magnetic pole 11 or the second magnetic pole 12.

In the first pattern, driving of the rotor 2 is controlled in a two-phase excitation state in which the first coil 4 and the second coil 5 are excited. In the second pattern, the driving of the rotor 2 is controlled in a one-phase excitation state in which only one of the first coil 4 and the second coil 5 is excited.

FIG. 3 is a perspective view showing the stator 3 having a more preferable shape. In FIG. 3, parts corresponding to the parts shown in FIG. 1 are denoted by the same reference numerals. The first magnetic pole 11 and the second magnetic pole 12 of the stator 3 are formed so as to face the peripheral surface of a rotor (not shown) and to correspond to the length of the rotor in the longitudinal direction, and to be vertically elongated. The stator 3 has arm portions 31 and 32 on both sides, and the arm portions 31 and 32 are connected to the base 35. The third magnetic pole 13 is formed at the center of the base 35. The third magnetic pole 13 is also formed in the same vertically long shape as the first magnetic pole 11 and the second magnetic pole 12.

[0029] In the present stator 3, coils 4 and 5 for exciting the first to third magnetic poles are wound around the arm portions 31 and 32, respectively. Projected shoulders 33 and 34 are formed at the rear end of each arm in order to position these coils 4 and 5 without displacement or winding. By providing the shoulder portions 33, 34 in this manner, the coils 4, 5 wound around the respective arm portions 31, 32 can be reliably positioned. And a structure for holding it in place. In addition, concave portions 37-39 are formed in the upper portions of the magnetic poles 11-13. The electromagnetic actuator 1 shown in the present embodiment is modularized by setting cases above and below it. These recesses 37-39 are used for positioning when setting the case.

As described above, the magnetic actuator 1 of the present embodiment can be manufactured efficiently because the magnetic pole formed at the end is located at a position that does not hinder the manufacturing process. In addition, since the range in which the magnetic poles are formed can be set relatively wide, the function as an electromagnetic actuator can be sufficiently ensured.

[0031] While a preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, but falls within the scope of the present invention described in the claims. Needless to say, the present invention can be applied to any type in which a coil can be wound around a stator, and various modifications can be made. Further, although the rotor 2 is exemplified as having four magnetic poles, the rotor 2 may have other magnetic poles.

Claims

The scope of the claims

[1] An electromagnetic actuator including a rotor and a stator wound with a coil disposed so as to face a part of the outer periphery of the rotor,

The stator is C-shaped,

The rotor is arranged such that a rotation axis of the rotor is present in a space surrounded by the stator,

When an imaginary reference line passing through the center of the rotation axis and separating the stator from side to side is set, each of both ends of the stator is shifted from the reference line to both sides around the position of the rotation axis. An electromagnetic actuator characterized by being formed in a range of not less than 90 degrees and not more than 90 degrees.

2. The electromagnetic actuator according to claim 1, wherein the stator is provided with a shoulder that suppresses displacement or winding of the coil.

[3] The stator has a third magnetic pole at an intermediate position between the first and second magnetic poles in addition to the first and second magnetic poles formed at the both end portions, respectively. The electromagnetic actuator according to claim 1 or 2, wherein the electromagnetic actuator is characterized in that:

4. The electromagnetic actuator according to claim 3, wherein the stator has a shape symmetric with respect to the virtual reference line.